// This file is part of libigl, a simple c++ geometry processing library.
// 
// Copyright (C) 2014 Alec Jacobson <alecjacobson@gmail.com>
// 
// This Source Code Form is subject to the terms of the Mozilla Public License 
// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
// obtain one at http://mozilla.org/MPL/2.0/.
#ifndef IGL_REMESH_SELF_INTERSECTIONS_H
#define IGL_REMESH_SELF_INTERSECTIONS_H
#include <igl/igl_inline.h>
#include "RemeshSelfIntersectionsParam.h"

#include <Eigen/Dense>

#ifdef MEX
#  include <mex.h>
#  include <cassert>
#  undef assert
#  define assert( isOK ) ( (isOK) ? (void)0 : (void) mexErrMsgTxt(C_STR(__FILE__<<":"<<__LINE__<<": failed assertion `"<<#isOK<<"'"<<std::endl) ) )
#endif
  
namespace igl
{
  // Given a triangle mesh (V,F) compute a new mesh (VV,FF) which is the same
  // as (V,F) except that any self-intersecting triangles in (V,F) have been
  // subdivided (new vertices and face created) so that the self-intersection
  // contour lies exactly on edges in (VV,FF). New vertices will appear in
  // original faces or on original edges. New vertices on edges are "merged"
  // only across original faces sharing that edge. This means that if the input
  // triangle mesh is a closed manifold the output will be too.
  //
  // Inputs:
  //   V  #V by 3 list of vertex positions
  //   F  #F by 3 list of triangle indices into V
  //   params  struct of optional parameters
  // Outputs:
  //   VV  #VV by 3 list of vertex positions
  //   FF  #FF by 3 list of triangle indices into V
  //   IF  #intersecting face pairs by 2  list of intersecting face pairs,
  //     indexing F
  //   J  #FF list of indices into F denoting birth triangle
  //   IM  #VV list of indices into VV of unique vertices.
  //
  // Known bugs: If an existing edge in (V,F) lies exactly on another face then
  // any resulting additional vertices along that edge may not get properly
  // connected so that the output mesh has the same global topology. This is
  // because 
  //
  // Example:
  //     // resolve intersections
  //     igl::remesh_self_intersections(V,F,params,VV,FF,IF,J,IM);
  //     // _apply_ duplicate vertex mapping IM to FF
  //     for_each(FF.data(),FF.data()+FF.size(),[&IM](int & a){a=IM(a);});
  //     // remove any vertices now unreferenced after duplicate mapping.
  //     igl::remove_unreferenced(VV,FF,SV,SF,UIM);
  //     // Now (SV,SF) is ready to extract outer hull
  //     igl::outer_hull(SV,SF,G,J,flip);
  //
  template <
    typename DerivedV,
    typename DerivedF,
    typename DerivedVV,
    typename DerivedFF,
    typename DerivedIF,
    typename DerivedJ,
    typename DerivedIM>
  IGL_INLINE void remesh_self_intersections(
    const Eigen::PlainObjectBase<DerivedV> & V,
    const Eigen::PlainObjectBase<DerivedF> & F,
    const RemeshSelfIntersectionsParam & params,
    Eigen::PlainObjectBase<DerivedVV> & VV,
    Eigen::PlainObjectBase<DerivedFF> & FF,
    Eigen::PlainObjectBase<DerivedIF> & IF,
    Eigen::PlainObjectBase<DerivedJ> & J,
    Eigen::PlainObjectBase<DerivedIM> & IM);
}

#ifndef IGL_STATIC_LIBRARY
#  include "remesh_self_intersections.cpp"
#endif
  
#endif
